Collings' screen breakthrough came playing the protagonist Raskolnikov in Fyodor Dostoyevsky's Crime & Punishment (1964 with Associated-Rediffusion Television).The production was recorded live.
He has played historical characters such as Percy Grainger in Ken Russell's Song of Summer (1968), John Ruskin in The Love School (1975), a BBC series about the Pre-Raphaelites, and Sir Anthony Babington in Elizabeth R. In 1975 he portrayed william Wilberforce in The Fight Against Slavery, and starred as william Pitt in Prince Regent in 1979.
Collings played the character of Bob Cratchit in the classic 1970 film musical, Scrooge, starring alongside Albert Finney, Dame Edith Evans, Sir Alec Guinness, Kenneth More, Anton Rogers and others.
He is also noted for his children's television appearances including the role of Julian Oakapple in Midnight is a Place (1977). In 1989 he played Charn (the villain) in Through The Dragon's Eye, and had a recurring role as the headmaster in Press Gang from 1989 to 1993.
In 1981, he played the dual roles of Lord Dark and The Friendly Ghost in the perennial school-children's favourite Dark Towers, part of the Look and Read series.
In 2006, Collings was the reader of the critically acclaimed recordings of The Complete Ghost Stories of M. R. James.
